Diff: main.cpp

Revision:

0:048fbd80203e

Child:

1:1d2208dce484

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Fri Sep 16 15:27:36 2016 +0000
@@ -0,0 +1,149 @@
+/**
+ * Minor BioRobotics 2016
+ *
+ * Programming Homework Set 2
+ * Exercise 2, example solution.
+ *
+ * Note that this problem can be solved in *much* cleaner ways, using slightly 
+ * more advanced C++ / programming techniques. However, this example shows that
+ * even with very basic programming skills quite a lot can be achieved.
+ *
+ * M.E. Grootens [at] utwente.nl,
+ * v0.1, 16.09.2016
+ */
+
+#include "mbed.h"
+
+// = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = >
+// Serial communication using MODSERIAL
+#define SERIAL_BAUD 115200  // baud rate for serial communication
+#include "MODSERIAL.h"
+MODSERIAL pc(USBTX,USBRX);
+
+// = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = >
+// Timing
+const float kTimeLedToggle = 0.25f; // period with which to toggle LED
+const float kTimePrintSerial = 1.0f;// period with which data is printed
+
+// = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = >
+// constants
+const int kNumLeds = 3;             // three LEDs
+const int kLedOn = 0;               // LED on if 0
+
+// LEDs
+DigitalOut led_0(LED_RED);
+DigitalOut led_1(LED_GREEN);
+DigitalOut led_2(LED_BLUE);
+
+// ID of led that should blink; *volatile* because changed by interrupt
+volatile int led_blink_id = 0;
+
+// counters
+int num_turned_on_0 = 0;            // count number of times red LED turned on
+int num_turned_on_1 = 0;            // count number of times green LED turned on
+int num_turned_on_2 = 0;            // count number of times blue LED turned on
+
+
+
+/**
+ * Toggle / Switch / Blink the state of the LED.
+ * Count the number of times the LED was turned ON.
+ * We have quite some duplicate code here; this is not ideal and could be solved
+ * using more 'advanced' concepts such as arrays and enums. 
+ * However, this is outside the scope of this course for now.
+ */
+void ToggleLed()
+{
+    switch (led_blink_id) {
+        case 0: {
+            // LED 0 to toggle and count:
+            led_0 = not led_0;
+            if (led_0 == kLedOn) {
+                num_turned_on_0++;
+            }
+            
+            // LEDs to turn off:
+            led_1 = not kLedOn;
+            led_2 = not kLedOn;
+            
+            break;
+        }
+        case 1: {
+            // LED 1 to toggle and count:
+            led_1 = not led_1;
+            if (led_1 == kLedOn) {
+                num_turned_on_1++;
+            }
+            
+            // LEDs to turn off:
+            led_0 = not kLedOn;
+            led_2 = not kLedOn;
+            
+            break;
+        }
+        case 2: {
+            // LED 2 to toggle and count:
+            led_2 = not led_2;
+            if (led_2 == kLedOn) {
+                num_turned_on_2++;
+            }
+            
+            // LEDs to turn off:
+            led_0 = not kLedOn;
+            led_1 = not kLedOn;
+            
+            break;
+        }
+    }
+}
+
+/**
+ * Print the number of times each LED was turned on through serial communication
+ */
+void PrintSerial()
+{
+    pc.printf("*Status*\r\n\tn_r = %d\r\n\tn_g = %d\r\n\tn_b = %d\r\n\r\n",
+        num_turned_on_0, num_turned_on_1, num_turned_on_2);
+}
+
+/**
+ * Switch the led id that blinks 
+ * led_blink_id goes from 0 -> 1 -> 2 -> 0 -> ...
+ * @ensure led_blink_id = ++led_blink_id % kNumStates
+ */
+void SwitchLedColor() {
+    led_blink_id++;
+    if (led_blink_id>=kNumLeds) {
+        // could also use modulo ('%') operator
+        led_blink_id = 0;
+    } 
+}
+
+/**
+ * Main loop.
+ */
+int main()
+{
+    // Serial comm baud rate
+    pc.baud(SERIAL_BAUD);
+    pc.printf("\r\n**RESET**\r\n");
+    
+    // Turn off all LEDs initially
+    led_0 = not kLedOn;
+    led_1 = not kLedOn;
+    led_2 = not kLedOn;
+    
+    // Create ticker and attach LED toggle function
+    Ticker tick_toggle_led;
+    tick_toggle_led.attach(ToggleLed,kTimeLedToggle);
+    
+    // Create ticker and attach Print function
+    Ticker tick_print_serial;
+    tick_print_serial.attach(&PrintSerial,kTimePrintSerial);
+    
+    // Create interrupt and attach switch function
+    InterruptIn sw2(SW2);
+    sw2.fall(&SwitchLedColor);
+    
+    while (true);
+}